LM321 - Audiometric Masking: Some New Ideas (Finally!)

Abstract:
The practice of audiometric masking is as unchanging as any topic in audiology. Masking is therefore unlikely to generate a high degree of enthusiasm. An exception to this would be for student clinicians learning about masking. It becomes an area of great interest---and often confusion. However, experienced clinicians might also be curious about underlying research that props up our practice of masking. What if this is also interesting? Masking is a foundational issue for accurate hearing assessment and new information has emerged. “Audiometric Masking: Some New Ideas (Finally!)” will review content connected to this important topic.

Summary:
The Plateau Method of masking was developed in the 1950s by a group of clinical researchers in Sweden. A plethora of masking writing, research, and technological developments followed for three or four decades. The activity and interest allowed for the masking knowledge base and practice to evolve in certain ways. For example, research on interaural attenuation and the occlusion effect was critical; the introduction of insert earphones to the market in the 1980s improved accuracy.

Despite masking being a foundational area of interest for those concerned with the accurate assessment of hearing (and for those attempting to learn about hearing assessment), the topic of masking as an energetic research area has slowed over the past twenty to thirty years.

Masking information delivered to the mass audience has also been lacking. For example, the most recent edition of the Katz Handbook of Clinical Audiology was the 7^th Edition published in 2015. The most recent book that included masking as a priority area was from 2009: a combined audiometry/masking resource that was heavy on the audiometry and quite light on the masking portion. Masking has typically been relegated to a single chapter within a combined textbook that covers a multitude of topics for audiology. A review of these chapters revealed that the writing and content about masking tends to be quite similar from author to author as the years passed.

The last book solely dedicated to audiometric masking was published in 1996. We were almost thirty years away from producing a dedicated text on this important topic.

This presentation will provide updated information that includes: Is there a better term that might replace “interaural attenuation?” The Optimized Method of masking. Masking for Word Recognition Score testing. What is situational interaural attenuation? Update on compensating for the occlusion effect. Compensating for central masking effects: yes or no? Recommendations for further research in several important areas.

A short “masking trivia” activity on these items will initiate the presentation as an ice-breaker. Example questions might include: What is a typical interaural attenuation value adopted when testing with insert earphones? What is the interaural attenuation value for bone-conduction? Have you heard of the Optimized Method of Masking? Should we compensate for central masking? Where was the plateau method invented?

The goal of the presentation will be to present attendees with a “deep-dive” into the data that has propped up the audiometric practice of masking for many years but which has often been communicated in a simplistic manner. Some contemporary writing and research will also be included. Some new approaches to the masking problem will be offered for consideration. Attendees will then have an opportunity to reflect on this content in relation to their own clinical practices.

Brief Summary of Clinical Takeaways:
The clinical takeaway for this session will result in exposure to updated information on masking theory and practice which should allow attendees to reflect on, or help develop, audiometric practices.